Use Tree to Display XML document
' *************************************************************
' * (C) Copyright 2003 by Deitel & Associates, Inc. *
' * and Prentice Hall. *
' * All Rights Reserved. *
' * *
' * DISCLAIMER: The authors and publisher of this book have *
' * used their best efforts in preparing the book. These *
' * efforts include the development, research, and testing of *
' * the theories and programs to determine their *
' * effectiveness. The authors and publisher make no warranty *
' * of any kind, expressed or implied, with regard to these *
' * programs or to the documentation contained in these books.*
' * The authors and publisher shall not be liable in any event*
' * for incidental or consequential damages in connection *
' * with, or arising out of, the furnishing, performance, or *
' * use of these programs. *
' *************************************************************
Imports System.Xml
Imports System.Windows.Forms
Imports System.CodeDom.Compiler
Public Class MainClass
Shared Sub Main()
Dim form1 As Form = New FrmXmlDom()
Application.Run(form1)
End Sub ' Main
End Class
Public Class FrmXmlDom
Inherits Form
' TextBox and TreeView for displaying data
Friend WithEvents txtConsole As TextBox
Friend WithEvents treXml As TreeView
' Buttons for building, printing and reseting DOM tree
Friend WithEvents cmdBuild As Button
Friend WithEvents cmdPrint As Button
Friend WithEvents cmdReset As Button
Private source As XmlDocument ' reference to "XML document"
' reference copy of source's "XML document"
Private copy As XmlDocument
Private tree As TreeNode ' TreeNode reference
Public Sub New()
MyBase.New()
' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the
' InitializeComponent() call
' create XmlDocument and load letter.xml
source = New XmlDocument()
source.Load("ExampleCode.xml")
' initialize references to Nothing
copy = Nothing
tree = Nothing
End Sub ' New
#Region " Windows Form Designer generated code "
'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
End If
MyBase.Dispose(disposing)
End Sub
'Required by the Windows Form Designer
Private components As System.ComponentModel.Container
'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.treXml = New System.Windows.Forms.TreeView()
Me.cmdBuild = New System.Windows.Forms.Button()
Me.txtConsole = New System.Windows.Forms.TextBox()
Me.cmdPrint = New System.Windows.Forms.Button()
Me.cmdReset = New System.Windows.Forms.Button()
Me.SuspendLayout()
'
'treXml
'
Me.treXml.ImageIndex = -1
Me.treXml.Location = New System.Drawing.Point(8, 40)
Me.treXml.Name = "treXml"
Me.treXml.SelectedImageIndex = -1
Me.treXml.Size = New System.Drawing.Size(344, 192)
Me.treXml.TabIndex = 3
'
'cmdBuild
'
Me.cmdBuild.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.cmdBuild.Location = New System.Drawing.Point(8, 8)
Me.cmdBuild.Name = "cmdBuild"
Me.cmdBuild.Size = New System.Drawing.Size(104, 23)
Me.cmdBuild.TabIndex = 0
Me.cmdBuild.Text = "Build"
'
'txtConsole
'
Me.txtConsole.Location = New System.Drawing.Point(8, 240)
Me.txtConsole.Multiline = True
Me.txtConsole.Name = "txtConsole"
Me.txtConsole.ScrollBars = System.Windows.Forms.ScrollBars.Vertical
Me.txtConsole.Size = New System.Drawing.Size(344, 96)
Me.txtConsole.TabIndex = 4
Me.txtConsole.Text = ""
'
'cmdPrint
'
Me.cmdPrint.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.cmdPrint.Location = New System.Drawing.Point(128, 8)
Me.cmdPrint.Name = "cmdPrint"
Me.cmdPrint.Size = New System.Drawing.Size(104, 23)
Me.cmdPrint.TabIndex = 1
Me.cmdPrint.Text = "Print"
'
'cmdReset
'
Me.cmdReset.Font = New System.Drawing.Font("Microsoft Sans Serif", 9.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
Me.cmdReset.Location = New System.Drawing.Point(248, 8)
Me.cmdReset.Name = "cmdReset"
Me.cmdReset.Size = New System.Drawing.Size(104, 23)
Me.cmdReset.TabIndex = 2
Me.cmdReset.Text = "Reset"
'
'FrmXmlDom
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(360, 341)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.txtConsole, Me.treXml, Me.cmdReset, Me.cmdPrint, Me.cmdBuild})
Me.Name = "FrmXmlDom"
Me.Text = "Xml Dom"
Me.ResumeLayout(False)
End Sub
#End Region
Private Sub cmdBuild_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles cmdBuild.Click
If Not copy Is Nothing Then
Return ' document already exists
End If
copy = New XmlDocument()
tree = New TreeNode()
tree.Text = source.Name ' assigns #root
treXml.Nodes.Add(tree)
BuildTree(source, copy, tree)
End Sub
Private Sub cmdPrint_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles cmdPrint.Click
If copy Is Nothing Then
Return
End If
Dim file As TempFileCollection = New TempFileCollection()
file.AddExtension("xml", False)
Dim filename As String() = New String(0) {}
file.CopyTo(filename, 0)
Dim writer As XmlTextWriter = _
New XmlTextWriter(filename(0), _
System.Text.Encoding.UTF8)
copy.WriteTo(writer)
writer.Close()
Dim reader As XmlTextReader = _
New XmlTextReader(filename(0))
While reader.Read
If reader.NodeType = XmlNodeType.EndElement Then
txtConsole.Text &= "/"
End If
If reader.Name <> String.Empty Then
txtConsole.Text &= reader.Name & vbCrLf
End If
If reader.Value <> String.Empty Then
txtConsole.Text &= vbTab & reader.Value & vbCrLf
End If
End While
reader.Close()
End Sub
Private Sub cmdReset_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles cmdReset.Click
If Not tree Is Nothing Then
treXml.Nodes.Remove(tree)
End If
treXml.Refresh()
copy = Nothing
tree = Nothing
txtConsole.Clear()
End Sub
Private Sub BuildTree(ByVal xmlSourceNode As XmlNode, _
ByVal documentValue As XmlNode, _
ByVal treeNode As TreeNode)
Dim nodeReader As XmlNodeReader = _
New XmlNodeReader(xmlSourceNode)
Dim currentNode As XmlNode = Nothing
Dim newNode As TreeNode = New TreeNode()
Dim modifiedNodeType As XmlNodeType
While nodeReader.Read
modifiedNodeType = nodeReader.NodeType
If modifiedNodeType = XmlNodeType.EndElement Then
modifiedNodeType = XmlNodeType.Element
End If
currentNode = copy.CreateNode(modifiedNodeType, _
nodeReader.Name, nodeReader.NamespaceURI)
Select Case nodeReader.NodeType
Case XmlNodeType.Text
newNode.Text = nodeReader.Value
treeNode.Nodes.Add(newNode)
CType(currentNode, XmlText).AppendData _
(nodeReader.Value)
documentValue.AppendChild(currentNode)
Case XmlNodeType.EndElement
documentValue = documentValue.ParentNode
treeNode = treeNode.Parent
Case XmlNodeType.Element
If Not nodeReader.IsEmptyElement Then
newNode.Text = nodeReader.Name
treeNode.Nodes.Add(newNode)
treeNode = newNode
documentValue.AppendChild(currentNode)
documentValue = documentValue.LastChild
Else
newNode.Text = nodeReader.NodeType.ToString
treeNode.Nodes.Add(newNode)
documentValue.AppendChild(currentNode)
End If
Case Else
newNode.Text = nodeReader.NodeType.ToString
treeNode.Nodes.Add(newNode)
documentValue.AppendChild(currentNode)
End Select
newNode = New TreeNode()
End While
treXml.ExpandAll()
treXml.Refresh()
End Sub
End Class
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